Study type: Medical/biological study (experimental study)

Chronic exposure to a 1.439 GHz electromagnetic field used for cellular phones does not promote N-ethylnitrosourea induced central nervous system tumors in F344 rats. med./bio.

Published in: Bioelectromagnetics 2005; 26 (1): 59-68

Aim of study (acc. to author)

To evaluate whether a 2 year exposure to an electromagnetic field equivalent to that generated by cellular phones can accelerate tumor development in the central nervous system of rats (brain tumorigenesis was initiated by an intrauterine exposure to N-ethylnitrosourea on gestational day 18).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.439 GHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 90 min/day, 5 days/week for 104 weeks
  • SAR: 2 W/kg average over mass (brain)
  • SAR: 6 W/kg peak value (brain) (time peak)
  • SAR: 0.67 W/kg average over mass (brain)
  • SAR: 2 W/kg peak value (brain) (time peak)
  • SAR: 0.4 W/kg average over mass (whole body)

General information

A total of 500 pups were divided into five groups: untreated control, ENU alone, ENU + EMF (two exposure levels + sham). N.B.: ENU treatment was done to their mothers on gestational day 18!

Exposure 1

Main characteristics
Frequency 1.439 GHz
Type
Exposure duration repeated daily exposure, 90 min/day, 5 days/week for 104 weeks
Modulation
Modulation type pulsed
Additional info

TDMA signal for the Japanese PDC (Personal Digital Cellular) system

Exposure setup
Exposure source
  • monopole
Distance between exposed object and exposure source 30 mm
Chamber The exposure box was 90 x 90 x 60 cm, the inside walls except for the ceiling being covered with electromagnetic absorber. Ten boxes were used simultaneously.
Setup Ten rats, fixed individually in plastic tubes (four different sizes), were set on a disk-shaped plate (65 cm in diameter) with their nose towards the center. A quarter-wavelength monopole antenna on the ceiling of the exposure box fitted in the center of the disk-shaped plate. The distance between the antenna and each rat nose was 30 mm and the distance between the ceiling and the rat back was 5 mm.
Additional info Plastic holders used were of four different sizes (inner diameter 4.0 cm, 4.7 cm, 5.5 cm, and 6.2 cm). If rats deceased, dummy rats were used to maintain symmetry and scheduled SAR in the exposure box.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg average over mass measured and calculated brain -
SAR 6 W/kg peak value measured and calculated brain time peak
SAR 0.67 W/kg average over mass measured and calculated brain -
SAR 2 W/kg peak value measured and calculated brain time peak
SAR 0.4 W/kg average over mass estimated whole body -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

There were no differences between the groups in body weights, food consumption, and survival rates. No increase in the incidences per group of brain and/or spinal cord tumors, either in the males or females, was revealed in the exposed rats. Additionally, no clear changes in tumor types were evident.
In conclusion, under the present experimental conditions, 1.439 GHz electromagnetic field exposure to the heads of rats for a 2 year period was not demonstrated to accelerate or affect N-ethylnitrosourea initiated brain tumorigenesis

Study character:

Study funded by

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